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J. BQJOHNSON. Electric Signal Bell. No. 242,135. Patented May 31,1881.

J/ 30 O O fi I yiE IU UNITED STATES PATENT OFFICE@ JOHN B. JOHNSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR OF ONEHALF TO ARTHUR P. WILSON, OF SAME PLACE.

ELECTRIC SIGNAL-BELL.

SPECIFICATION forming part of Letters Patent No. 242,135, dated May 31, 1881. Application filed February 27, 1880.

To all whom it may concern Be it known that I, JOHN B. JOHNSON, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Electrio Signal-Bells, of which the following description, in connection with the accompanying drawings, is a specification.

My invention relates to an electric signalbell and it consists,mainly,in the combination of the following elements-namely, an electromotor, a circuit-closer to control it, and a bellhammer operated by the said motor to give a series of strokes at uniform intervals of time while the motor remains in operation, and a circuit-breaker operated by the said hammer in making its stroke, and a repeating or indicating signal in a circuit controlled by the said circuit-breaker to inform the operator controlling the main signal-bell of its operation.

The invention, also consists in details of construction of the elcctro-motor, and in certain combinations of devices to be hereinafter more fully described.

The main bell-hammer is raised by a spiral cam, and is retracted by a spring to strike the bell. In its downstroke the hammer arm operates a circuit-breaker, which causes the repeating-bell to give a tap; but as the hammer passes it the circuit is again closed, so that the action of the eleclro-motor is not perceptibly checked. This circuit-breaker is so constructed that it is not caused to break the circuit asthe bell-hammer passes it in its upward movement, as if this were to happen the whole instrument would immediately cease to act.

Figure 1 is a front elevation of the signal-strikin g mechanism, the front plate being removed. Fig. 2 shows the apparatus at the signalingpoint; Fig. 3, a plan view of the commutator detached, and Fig. 4 a rear view of a portion of the mechanism shown in Fig. 1.

Referring to Fig. 1, the main signal mechanism is supported between two main frameplates, the rear one, a, only of which is shown;

but the front one is justlikeit and is attached to the posts a Attached to the rear plate, a, are two brackets,'a a, sustaining two electro-magnets, b c, the coils of which maybe alternately brought into an electric circuit by the commutator d, supported on a bracket, w, to cause the armature e to be attracted first by b and then by c, and thus receive a rapid vibratory motion.

The armature c is carried on a lever, f, pivoted at 2 between the frame-plates, the said lever being prow ided with an upwardly extending finger, 3, to operate the commutator, as hereinafter described.

The lower end of the arm f is provided with a pawl, g, pressed by a spring, 9, against the teeth of a ratchet-wheel, i, on an arbor, 4. A second arm f, pivoted at 5, and provided with a similar pawl, 9, caused by a spring, 9 to engage the ratchet-wheel i on the side opposite to the pawl g, is connected by a link, j, (see Fig. 4,) to the armf, the said link being pivoted to the arms f f at the points 6 7, and causing any oscillatory motion applied to the arm f by the armature e and electro-magnets b c to be transmitted to the armf.

The pivotal points 2 5 of the arms ff, as well as the pivotal points 6 7 of the link j, are symmetrically arranged with relation to the arbor 4, so that the pawls gg each move the ratchet-wheel z the same distance.

In the drawings the arrowsindicate the movement of the parts while the magnet c is magnetized, the pawl gthen slipping over and the pawl g engaging the teeth of the ratchet-wheel and causing it to rotate in the direction of the arrow. When the magnet b, in turn, becomes magnetized the arms f f will move in the opposite direction, and the pawl 9 will now act on teeth of the wheel 7;, causing it to rotate in the same direction as before, while the pawl g will slip over the said teeth. The ratchetwheel 6 and its arbor 4 will thus receive a constant rotary motion in one direction as long as the electro-magnetic apparatus is in electric circuit.

An electro-motor constructed on this principle has no dead-centers and requires no flywheel, and is more powerful and certain in its operation than one acting on a crank-pin or equivalent in the usual manner.

A spiral cam, k, upon and rotating with the arbor 4, engages a pin, 8, on the hammer-arm l, pivoted at 9 on a stud upon the plate a, and swings the hammer back until the radial part 10 of the said cam comes opposite the pin 8, when the hammer-arm is drawn forward by the spring M into the position shown in dotted lines, Fig. 1, to strike a gong, the position of which is indicated by the dotted line a. The continuous rotation of the arbor 4 and cam I. will thus cause a series of blows to be struck on the gong as long as the apparatus is in electric circuit.

The apparatus at the signalstation consists of a circuit-closing key, 0, shown as one of the usual button-keys, and a repeating-bell, p, the hammer p of which is carried by a rod, 11, pivoted at 12, and provided with an armature. 13, controlled by an electro-magnet, l", which, when in circuit, holds the hammer p away from the bell p, but when demagnetized allows the hammer to fall under the action of its weight and the spring 14 to sound the bell p. A stop, 15, limits the downward movement of the hammer-rod 11.

The circuit of the signal-actuating battery B is as follows: One pole is connected by a wire, 20, with a metal piece, 21, supported on an insulating-block, 22, on the frame a. The metal piece 21 thus has itself no electric connection with the metal frame-work, but it terminates in a flexible tongue, 23, adapted to make elec trical connection with the circuit-breaker .v, pivoted at 16 to the plate a, and in electrical connection therewith, so that when the said circuit-breaker a is in contact with the tongue 23, as shown in full lines, Fig. 1, which is its normal condition, being so held by the spring 17, the current passes to the metal frame-work and mechanism, which is connected by the wire 24 with the insulated metal plate 25 of the comniutating device (I. This plate 25 is always in contact with the ('ommutating-slide, shown as a small metal flame, 26, provided with two lateral bow-shaped springs, 27 28, which press against the ledge 18 of insulating material on one side and against the metal strips 25 50 31 on the other side, the whole slide being free to move longitudinally with a slight friction, which holds it in any position in which it may be left until positively moved therefrom.

One end of the sprin 28 rests always in contact with the plate 25, as before mentioned, while the other end is provided with a small stud, 29, adapted to form electrical contact with one or the other of the plates 31, according to the position of the slide. When the stud 29 is in contact with the plate 30 the circuit passes therefrom by the wire 33, connected with the said plate, through the coils of the elcctro-magnet I), and thence by wire 31 to the wire 40, and when the said stud 29 touches the plate 31 the circuit follows the wire 35 through the coils of the electro-magnet 0, connected by wire 36 with wire 40, and in either case the circuit is completed through wire 40, key 0, coils of the electro-magnet r, and wire 41 to the other pole of the battery B.

The construction and operation of the commutator are as follows: The slide 1 being in the position shown in Figs. 1 and 3, connecting the plates 25 and 31, the magnet 0 will be in circuit, and, provided the circnitis held closed at the key 0 by the operator, the said magnet 0 will be magnetized and attract the armature 0, thus oscillating the arms ff, as before described. In the movement of the armature 0 up to the poles of the magnet c the finger 3 will pass across the openingin the frame 26 of the slide 2, and toward the end of its movement will meet the adjustable point 50, shown as a screw in a lug at the end of the said frame, and will move the slide t with it to bring the stud 29 in contact with the plate 30, thus placing the magnet 0 out of and the magnet b in circuit. For a moment the stud 29 will touch both plates 30 31 but the armature a will then be so much nearer the magnet toward which than that from which it is moving that it will complete its movement, as described. The clectro-magnet I; now being magnetized, the armature 0 will move toward it and the finger 3 first pass across the open space between the points 51, and then strike the point 51 simi lar to 50 and shift the slideback to connect the plates 25 31, and this movement will continue as long as the operator holds the circuit closed at 0, the wheel 2' and cam 75 being rotated, as before described, to give a series of strokes on the gong at uniform intervals of time.

In order that the operator at the key 0 may be informed of the operation of the gong, so that he may send a signal, represented by any predetermined number of blows on the gong, the repeating-bell p is used, and is herein shown as placed in the main circuit.

If the circuit be broken, the hammer 12 will give a tap on the hell 1), and in practice this is accomplished by the circuit-breaker s, operated by the pin on the hammer-arm l in its downstroke. The said circuit-breaker .sis provided with a pawl, 11, pivoted also at 16, and free to turn independently of the circuitbreaker s in the direction of the arrow 70, but acting on the pin 19, against which it is normally held by a spring, 18, to turn the circuitbreaker s in the direction of the arrow 80.

In the rapid downstroke ot' the hammer caused by its spring at the pin 60 strikes the toe a of the pawl a and causes it; and the circuit-breaker to swing together on the point 16 into the position shown in dotted lines, thus breaking the circuit at 23. When the point tit) passes the tee a the circuit-breaker s snaps back under the influence of the spring 17, and the operation is so quickly accomplished that the action of the motor is not perceptibly checked, but asingle tap is sounded on the Dell 19.

In the upstroke of the hammer the pin 60 merelycauses the pawl a to turn away from the pin 19 without operating the circuit-breaker s.

A commutator of the kind herein described allows the armature to make its full movement under the influence of the electro-inagnet in circuit, as it does not shift the slide until just at the end of said movement, and the proper action is readily attained by adjusting the points 50 51.

A signal-bell constructed on this principle is preferable for many purposes toa single-tap bell operated by a key, as it removes the liability of mistakes in such arising from careless or rapid manipulation;

Any well-known means for producing an electric current may be used as an equivalent for the battery shown.

It is obvious that any other form of signal besides the tap-bell shown may be used as an indicator or repeater to indicate the operation of the main signal.

I claim- 1. In an electric signaling apparatus, an electro-motor, a circuit-closer to control it, and a bell-hammer operated thereby, combined with a circuit-breaker, operated by the said bellhammer in its downstroke, and a repeating or indicating signal in acircnit, operated by the said circuit-breaker, substantially as described.

2. In an electric apparatus, the combination, with a ratchet-wheel, of a pivoted armature- 2 5 arm and armature thereon, adapted to receive a vibratory or oscillating movement under the influence of one or more electro-magnets, and a second arm independent of and connected by a link with the first, and a pawl carried by 0 each of said arms to alternately engage the said ratchet-wheel and impart to it a rotary motion in one direction.

3. The combination, with a bell-hammer, of a circuit-breaker adapted to be operated by 5 the said bell-hammer in its downstroke, but to allow the hammer to pass in its upstroke withoutoperating the said circuit-breaker, substantially as described.

In testimony whereof I have signed my name 0 to this specification in the presence of two subscribing witnesses.

JOHN B. JOHNSON.

Witnesses:

J os. P. LIVERMORE, N. E. O. WHITNEY. 

